Furniture wheels

ABSTRACT

1. A furniture support swivel wheel unit comprising a wheel mounted rotatably in a wheel holder, the wheel holder being swingably about a vertical shaft the axis of which is horizontally spaced from the axis of rotation of the wheel, said shaft being operable to swingably connect said wheel unit with the lower end of a furniture leg, the wheel being mounted so as to be vertically movable relatively to the shaft and associated with a spring for biasing the wheels in downward direction, the wheel holder having a lower surface which is operable to be rested plane against the floor in response to the wheel unit being pressed downwardly relatively to the wheel against the action of the bias. The bias is adjusted in such a manner that the piece of furniture is supported on the wheels when in unloaded position, whilst said lower surface of the wheel holder is pressed down against the floor when the furniture is loaded.

United States Patent Bruun 1 Sept. 18, 1973 FURNITURE WHEELS [57] ABSTRACT [76] Inventor: Bruun Busha-lve-l Holblerg l. A furniture support swivel wheel unit comprising a Denmark wheel mounted rotatably in a wheel holder, the wheel [22] Filed: June 17, 1971 holder being swingably about a vertical shaft the axis of which is horizontally s aced from the axis of rotation [21] Appl' 154301 of the wheel, said sha t being operable to swingably connect said wheel unit with the lower end of a furni- [52] U.S. Cl. 16/44, 182/ 15 ture g, the h l ing mo nt d so as to be ertically [51] Int. Cl A47b 91/00 movable r l i ly to he shaf nd associated with a [58] Field of Search 16/44, 40, 19, 18; Spring for biasing the wheels in downward direction,

188/5; 182/15 the wheel holder having a lower surface which is operable to be rested plane against the floor in response to [56] Referen e Cit d the wheel unit being pressed downwardly relatively to UNITED STATES PATENTS the wheel against the action of the bias. The bias is ad- 2 891,764 6/1959 Peame u 16/44 justed in such a manner that the piece of furniture is Primary ExaminerFrancis K. Zugel Assistant Examiner-Doris L. Troutman Attorney-Craig, Antonelli & Hill //I/IIII//IIIIIII n\ supported on the wheels when in unloaded position, whilst said lower surface of the wheel holder is pressed down against the floor when the furniture is loaded.

7 Claims, 5 Drawing Figures M II V 4 I f6 2 a l 10 1; 1 2 D' I I 12 3 g 50 I I z a D I ''IIIIIIIIIIIIITIIIII// "Ill/111A PATENTEI] SEN 8 I975 SHEET 1 BF 2 INVENTOR.

KAI BRUUN A TTORNE Y8 PATENTEU SE?! 8 I975 SHEET 2 OF 2 INVENTOR.

KAI BRU UN BY QQJ MM 4 H-LQQ ATTORNEYS.

FURNITURE WHEELS The present invention relates to a support wheel or roller for mounting at the lower end of a furniture leg so as to make the piece of furniture easily movable on the floor. More specifically the invention relates to furniture wheel comprising a wheel holder or bracket to be mounted under a furniture part such as a sofa leg in such a manner that the wheel holder with the wheel is swingable about a vertical axis spaced horizontally from the axis of rotation of the wheel.

Such swivel wheels have been used extensively in connection with e.g., office chairs and movable tables, but now there is a tendency to also use such wheels in connection with many private lying and sitting furnitures, especially heavier chairs and sofas. These pieces of furniture are then easier to move, since the wheels will automatically be turned into an operative position when the furniture is simply pushed or pulled in any arbitary horizontal direction. According to their nature the wheels, however, will transfer the entire weight of the piece of furniture to a very little area of the floor or the floor carpet whereby the same may be damaged or at least receive undesired pressure marks, especially when the furniture is loaded. Furthermore, it is normally not desirably that these pieces of furniture are easily movable in their loaded condition.

In order to counteract these difficulties it would be possible to mount an inverted bowl member underneath the furniture leg and around the swivel wheel, and in that connection suspend the wheel with a certain vertical movability so as to obtain that in loaded condition the furniture will be heavy enough to overcome a spring bias acting on the wheel and thereby to press down the lower edge of the bowl member against the floor, whilst the wheel is relatively pressed upwardly inside the bowl member. The said spring should be adjusted so as to relatively lower the wheel, i.e., lift the furniture up from the bowl supported position, when it returns to its unloaded condition. Hereby the loaded piece of furniture would be supported not only by the wheels, but-also by the edges of the bowl members, i.e., with an increased area of the supporting surfaces and thus with a resulting lower floor pressure per square unit. However, if the wheel shall be mounted in a reasonably effective distance from its vertical swivel axis the interior diameter of the bowl member should be considerable, whereby the bowl member would become a very dominating element.

In the main aspect of the present invention it is the purpose of the invention to provide a furniture wheel unit which, without being correspondingly dominating, may serve as an ordinary swivel wheel when the furniture is unloaded and as a broad area supporting member when the furniture is loaded. According to the invention there is provided a wheel unit in adapted the wheel is mounted so as to be vertically movable-relatively to that part of the unit which is adpate to be fixed to the furniture part to be supported, the wheel hereby being upwardly movable against the action of the permanent force such as a spring force, said unit having a lower support surface with which the unit can rest on the floor when the wheel assumes a pressed up position, said support surface being directly associated with the said wheel holder or a bracket so as to be turnable together therewith and preferably being constituted by a plate shaped underside of the wheel holder.

When the broad support is turnable together with the wheel and the wheel holder there will be no need to provide an open central space allowing the wheel to be turned all the way round, i.e except for the actual area of the contact between the wheel and the floor the remaining underside of the wheel holder may be used as a support surface whereby a sufficiently enlarged support surface may be obtained without the total width of the wheel unit being much broader than the well known rigid swivel wheel units and anyway smaller than the turning diameter of the wheel.

In the following the invention will be explained in more detail with reference to the accompanying drawing, in which:

FIGS. 1 and 2 are sectional views of an embodiment ofa wheel unit according to the invention, shown in unloaded, respectively loaded condition, and

FIGS. 3-5 are sectional views of a preferred embodiment shown in the three geometrical main planes.

In FIG. 1 is shown a sofa leg 2. It is in well-known manner provided with a bore 4 receiving a holding bushing 6 for a shaft or pin 8 carrying at its lower end a wheel unit comprising a wheel 10 and a wheel bracket 12 in which the wheel shaft 14 is off-set from the vertical axis of the pin 8. When the sofa is supported by such wheels under all legs it may be pushed or pulled in any direction on the floor, since the wheel units will automatically adjust themselves by swinging in the bushings 6 so as to get the wheel planes lined up in the direction of the movement.

According to the invention the wheel 10 is supported so as to be vertically movable relatively to the sofa leg. in the embodiment shown this is obtained by means of a pivotal connection 16 between the wheel bracket 12 and the pin 8, as shown; a cross pin 16 is mounted at the outer end of an arm 18 projecting horizontally out from the lower end of the pin 8 in direction opposite of the wheel 10. Between a closed bottom disc portion 20 of the bracket 12 and the lower end of the pin 8 there is inserted a compression spring 22 held by a pin 24, the top end of which may be received in a depression 26 in the lower end of the pin 8 when the wheel bracket is swung upwardly about the cross pin 16.

The lower end of the spring may be rested directly on the bracket bottom 20 (as shown in FIG. 2), but preferably there is provided an arrangement for adjusting the initial length and therewith the initial force of the spring, and in the embodiment shown this arrangement comprises a V-shaped member 28 having bifurcated branch ends of which the lower end 30 extends beyond the pin 24 at both sides thereof so as to serve as a support for the lower end of the spring 22, whilst the upper end 32 of the V-member 28 engages a nut 34 on a screw 36, this screw being held in position by means of a cross member 38 in the bracket. The nut 34 is provided with flat sides and is prevented from rotation by means of side flaps 40 on the branch 32. The bottom or corner of the V-member 28 is rested against the corner of the bracket so that an adjustment of the screw 36 will cause the nut 34 to move and thereby the lower branch end 30 to be raised or lowered for adjusting the spring tension.

The spring tension is chosen or adjusted in such a manner that it holds the sofa in a slightly raised position when the sofa is unloaded, but not when the sofa is loaded, e.g., by the extra weight of a person sitting therein. In this case the spring will be compressed and the sofa lowered so that the wheel bracket is swung to the position shown in FIG. 2, in which it constitutes a rigid distance piece between the sofa leg and the floor, resting on the floor with the relatively large bottom plate portion 20; this portion is tangential to the wheel so that the wheel itself does not press against the floor, or at least not with any big pressure.

As indicated in dotted lines in FIG. 2 the bracket 12 may be rigidly connected to the pin 8 if the wheel shaft 14 is guided in vertical side slots 50 in the bracket, and biased in downward direction by means of a spring member 52. When the load is relieved from the sofa this spring will be to raise the sofa leg and thus lift the large support surface up from the floor so that the leg 2 is thereafter supported by the wheel 10 only.

It will even be within the scope of the invention to arrange the wheel outside the leg 2 in a bracket which is adapted to remote freely about the leg, so that the large support surface will be constituted by the underside of the leg itself.

The preferred embodiment shown in FIGS. 3-5 comprises an elongated wheel box 60 which adjacent the middle thereof is provided with an upwardly open passage 62 for receiving a shaft pin 64, the upper end of which is adapted to be received in a lower bore 66 in the furniture leg 2 in such a manner that the top side of the box is situated slightly below the end of the leg. By means of friction rings 68 the pin 64 is prevented from unintentional retraction from the bores 62 and 66, respectively. The wheel roller 10 is mounted between two intermediate wall portions 70 at one end of the box 60 with its shaft 14 projecting out through vertical slots 72 in these walls. The wheel box is closed by means of a bottom plate 74 in which there is provided a hole 76 through which the lower side of the wheel 10 may project downwardly.

In the other end of the box 60, in the lower part thereof, there is mounted a pivot member 78 having a bowl shaped bottom portion 80 which at the rear engages an elevated edge portion 84 of the bottom plate 74 with a collar portion 82. This pivot member has a middle hole receiving an annular flange 86 projecting upwardly from the bottom plate 74. Through this flange there extends an upright adjustment screw 88 having at its lower end a kerb head 90 countersunk in the bottom plate 74. At its upper end the screw 88 has a nut 92 which is in any suitable manner (not shown) locked against rotation, e.g., by means of guiding ribs projecting downwardly from the top side of the box; this nut is provided with a stop flange for the upper end of a compression spring 94 which at its lower end en-' gages the bottom of the bowl member 80. The pivot member 78 has a pair of forwardly protruding arms 96 each extending along the exterior side of the opposed intermediate walls 70 and having a frontmost flange portion 98 pressing down on the projecting ends of the wheel shaft 14. The bottom plate 74 is secured to the I remaining box 60 by means of screws 100.

The stop nut 92 is adjusted to such a position on the screw 88 that the arms 96 press down the wheel shaft 14 with a force which is just sufficient to maintain the wheel in its lower position when the furniture is unloaded. When it gets loaded the spring 94 will be compressed and thereby allow the entire bottom plate 74 to be lowered down onto the floor.

It will be appreciated that this embodiment combines an attractive appearance with good space facilities for the mounting of a very robust spring system and a large supporting surface due to the fact that the wheel box is made symmetrical about its vertical cross plane through the pin 64.

In a simplified embodiment indicated in dotted lines in FIG. 3 the pivot member 78 with the arms 96 as well as the spring 94 may be substituted by a lying coil spring 102 having straight end pieces 104 substituting the arms 96 and having a bent out middle portion 106 anchored to a holding portion 108 of the wheel box. The spring tension will here be adjustable e.g., by means of a rigid spring core 110 received on the screw.

What is claimed is:

1. A furniture support swivel wheel unit comprising a wheel mounted rotatably in a wheel holder, said wheel holder being swingable about a vertical shaft the axis of which is horizontally spaced from the axis of rotation of said wheel, said shaft being operable to swingably connect said wheel unit with the lower end of a furniture leg, said wheel being mounted so as to be vertically movable relative to said shaft, means for biasing said wheel in downward direction, said wheel holder having a lower surface which supports the furniture in response to the wheel unit being pressed downwardly relatively to said wheel against the action of said bias, and adjustment means, provided with said wheel holder, for effecting adjustment of said wheel bias so as to counterbalance the weight of the furniture on said wheel unit.

2. A furniture support swivel wheel unit as claimed in claim 1, in which said wheel holder is a substantially closed housing the underside of which is plane and provided with an opening, said wheel being mounted inside said housing so as to be vertically movable between a lower position in which the lower portion of the wheel projects down through said opening and a raised position in which the lower side of the wheel is in flush with said underside of said housing, said means for biasing being arranged between said wheel and a part of said housing said housing being associated with said vertical shaft so as to be swingably about the axis thereof but otherwise substantially non-displaceable and nonpivotal relatively thereto.

3. A furniture support swivel wheel unit according to claim 2, in which a wheel shaft of said wheel projects out through substantially vertical guiding slots in opposed wall portions of said housing, said means for biasing being arranged so as to engage the top side of said wheel shaft and press the same downwardly 4. A furniture support swivel wheel unit according to claim 2, in which said housing is provided with a hole for receiving said vertical shaft.

5. A furniture support swivel wheel unit according to claim 3, in which said means for biasing is arranged inside said housing horizontally off set from said wheel and connected to said wheel shaft by means of pressing arm means extending substantially horizontally between said means for biasing and said wheel shaft.

6. A furniture support swivel wheel unit according to claim 5, in which said pressing arm means are constituted by a stiff member having a base portion and a bifurcated pressing arm portion, said pressing arm portion engaging the top side of said wheel shaft, said base portion being vertically pivotally connected to said housing by its end remote from said pressing ann portion, said means for biasing is interposed between a stop member rigidly connected with said housing and said base portion of said stiff member.

7. A furniture support swivel wheel unit according to claim 6, in which the position of said stop member is adjustable relatively to said housing.

t i i I I! 

1. A furniture support swivel wheel unit comprising a wheel mounted rotatably in a wheel holder, said wheel holder being swingable about a vertical shaft the axis of which is horizontally spaced from the axis of rotation of said wheel, said shaft being operable to swingably connect said wheel unit with the lower end of a furniture leg, said wheel being mounted so as to be vertically movable relative to said shaft, means for biasing said wheel in downward direction, said wheel holder having a lower surface which supports the furniture in response to the wheel unit being pressed downwardly relatively to said wheel against the action of said bias, and adjustment means, provided with said wheel holder, for effecting adjustment of said wheel bias so as to counterbalance the weight of the furniture on said wheel unit.
 2. A furniture support swivel wheel unit as claimed in claim 1, in which said wheel holder is a substantially closed housing the underside of which is plane and provided with an opening, said wheel being mounted inside said housing so as to be vertically movable between a lower position in which the lower portion of the wheel projects down through said opening and a raised position in which the lower side of the wheel is in flush with said underside of said housing, said means for biasing being arranged between said wheel and a part of said housing said housing being associated with said vertical shaft so as to be swingably about the axis thereof but otherwise substantially non-displaceable and non-pivotal relatively thereto.
 3. A furniture support swivel wheel unit according to claim 2, in which a wheel shaft of said wheel projects out through substantially vertical guiding slots in opposed wall portions of said housing, said means for biasing being arranged so as to engage the top side of said wheel shaft and press the same downwardly
 4. A furniture support swivel wheel unit according to claim 2, in which said housing is provided with a hole for receiving said vertical shaft.
 5. A furniture support swivel wheel unit according to claim 3, in which said means for biasing is arranged inside said housing horizontally off set from said wheel and connected to said wheel shaft by means of pressing arm means extending substantially horizontally between said means for biasing and said wheel shaft.
 6. A furniture support swivel wheel unit according to claim 5, in which said pressing arm means are constituted by a stiff member having a base portion and a bifurcated pressing arm portion, said pressing arm portion engaging the top side of said wheel shaft, said base portion being vertically pivotally connected to said housing by its end remote from said pressing arm portion, said means for biasing is interposed between a stop member rigidly connected with said housing and said base portion of said stiff member.
 7. A furniture support swivel wheel unit according to claim 6, in which the position of said stop member is adjustable relatively to said housing. 